456 THE POPULAR SCIENCE MONTHLY 
coveries and theories. I might say, however, that there are strong rea- 
sons for believing in the molecular structure of electricity, the electrical 
nature of matter and the dependence of mass upon velocity. The the- 
ories of radioactivity and disintegration of matter are fairly well estab- 
lished. According to Ramsay, one of the most eminent chemists in the 
world, “ we are on the brink of discovering the synthesis of atoms, which 
may lead to the discovery of the ordinary elements.” Perhaps the 
dream of the alchemist is about to be realized. Certain it is that we 
are face to face with energies of which no one even dreamed a few years 
ago. Whether we call this energy intra-atomic, sub-atomic, inter-ele- 
mental, or some other name, we know certainly that it exists, and that 
it exists in quantities far beyond the power of man’s mind to compre- 
hend. Man dares to hope, some day, somewhere, somehow, to discover 
the means of unlocking this infinite storehouse. If this discovery is 
ever made, all the others which man has ever made will pale into insig- 
nificance beside it. 
Lodge says of the one-pound shot and the one-hundred-pound shot 
which Galileo dropped from the top of the Leaning Tower, that “ their 
simultaneous clang as they struck the ground together sounded the 
death knell of the old system of philosophy and heralded the birth of 
the new.” The age of reverence for authority had passed away and 
the day of experimental investigation had dawned. 
In a sense the discoveries of the past few years have resulted in a 
similar revolution. The revival of the experimental method has been 
complete. Accepted theories are being put to the test. What we have 
long regarded as proved facts are being questioned and, in many cases, 
challenged. There is no field of investigation which has not been cul- 
tivated anew. 
In closing, I wish to quote from the presidential address of J. J. 
Thomson before the British Association at its last meeting. 
The new discoveries made in physics the last few years, and the ideas and 
potentialities suggested by them, have had an effect upon the workers in that 
subject akin to that produced in literature by the Renaissance. Enthusiasm 
has been quickened, and there is a hopeful, youthful, perhaps exuberant, spirit 
abroad which leads men to make with confidence experiments which would have 
been thought fantastic twenty years ago. It has quite dispelled the pessimistic 
feeling not uncommon at that time, that all the interesting things had been 
discovered, and all that was left was to alter a decimal or two in some physical 
constant. There never was any justification for this feeling, there never were 
any signs of an approach to finality in science. The sum of knowledge is, at 
present at any rate, a diverging, not a converging series. As we conquer peak 
after peak we see regions in front of us full of interest and beauty, but we do 
not see our goal, we do not see the horizon; in the distance tower still higher 
peaks, which will yield to those who ascend them, still wider prospects, and 
deepen the feeling, whose truth is emphasized by every advance in science, that 
“ Great are the Works of the Lord.” 
8 Scientific American Supplement, 63, Nos. 1757 and 1758, pp. 154, 155 and 
174-176, September 4 and 11, 1909. 
